Schematic for brake lines wanted

[Popanz]

Hello,

I need a schematic for the brake line routing of my 77 Fourgonnette. I have a master cylinder with 4 connections and a brake pressure valve in the rear with 3 connections. Can anybody help ?????

Thank you and regards from Hannover

Hjalmar

[ervaar.R4]

Could you be more specific ?
Do you want to know how the brake-lines are connected ?
Or just a drawing ? Like this:

CLICK on the image:

[Tweety]

I have a master cylinder with 4 connections and a brake pressure valve in the rear with 3 connections.

That is not so good... if the mastercylinder has 4 connections, the proportionervalve should also have 4 connections... , eg they should have the same amount of connections... you have a mixed up combination of parts... no drawing is going to help except maybe this...

[Tweety]

Oh hold on i've never seen that splitter thing-before in the final rear brake line... anyway that does leave one thing... on the mastercylinder the first 2 connections go to the front brakes, then there are 2 lines that go to the rear, with different wartel size... the big size goes on the big size on the proportioner valve... the small one goes to 1 of the small ones on the proportioner valve, now in case of doubt (because we have 2 options left there...) you have connected it correctly if... when the rear-brakes are to be limited... so when the left rearwheel comes of the ground... no brakefluid comes out toward the rear-brakes.... ! and i think the little wartel that is facing either up or forwards goes to the mastercylinder....

[Popanz]

@ervaar.R4:

yes, a drawing like the one you ad is helpful.

@ tweety:

thank you, great discription !!!! I took everything apart and made photos but only from the rear. So I do not remember how everything was connected to the master cylinder.

[Bertje]

So I guess the issue is solved by the picture of ervaar.R4? Otherwise I could send you a pic of how the 4 connection rear pressure valve is connected: the 2 connectors that are at equal height each serve one of the rear wheels, the one pointing to the left actually serves the right wheel, the other is connected by a (very) short brake line to the brake tube (is that correct English?) of the left wheel. The remaining 2 connections can't be mixed up since they have different sized connectors...

But I guess your set-up is just the one ervaar.R4 posted

[Tweety]

Otherwise I could send you a pic of how the 4 connection rear pressure valve is connected::

hey bertje he had one with 3 connections... read....

[Popanz]

I took all the old brake lines and tried to reconstruct the routing. I think I have got everything together again. Thank you all of you !

Here it is how it was assembled:

From the master cylinder the first two lines go to the front brakes. The next two lines (one with big and one with small connector) go to the rear of the car. The line with the big connector go to the middle hole of the propertional valve. From the right hole of the proportional valve the line goes to the left rear brake. From the left hole of the propotional valve a short line goes to a 2-way splitter next to the proportional valve. From here one line goes to the right rear brake and the other line is the long line from the master cylinder with the small connector.

Confused ????

Hjalmar

[Bertje]

Otherwise I could send you a pic of how the 4 connection rear pressure valve is connected::

hey bertje he had one with 3 connections... read....

But I guess your set-up is just the one ervaar.R4 posted

ervaar.R4 posted a schematic of the 3 connector type... So I did realize that Hjalmar had a pressure valve with 3 connectors. The thing is, since his main brake cylinder has 4 connections I guess he could upgrade to a 4 connector pressure valve and get rid of this splitter (which seems a bit fault-prone to me...)

Hjalmar, the way I understand your explanation you connected things incorrectly... Both lines that come from the main brake cylinder need to go to the pressure valve and then from the pressure valve via the splitter to both rear wheels. The way you connected it I guess the pressure valve only controls the brake pressure on the left. So in case of an emergency stop your right rear wheel will block and your car will spin to the left!

[Popanz]

How can I ad a picture ????

I found a photo of the rear where you can see all the connections. I seems to me that the way I said was original. What are the two lines going from the master cylinder to the rear for ? Is one line a return line ? Do both have the same preasure ?

I do not know how I can ad a picture....

Hjalmar

[Hanz]

How can I ad a picture ????

description here. If you don't understand (it's in dutch), you can send me the picture: hanz99 - at - gmail - dot - com

[Popanz]

The two lines coming from the left of the picture are the ones from the master cylinder. The one on top is the one with the bigger connector.

[Bertje]

I alway thought the second line is just for safety; so it's a double circuit in case one of the lines get clogged. That would also explain why on some older models you see a single line.

It could of course be the case that how it was "originally" connected just wasn't "original" but a mistake from a previous owner. Did you check ervaar.R4s schematic already? To me it sounds as if that is your set-up (or rather: how it should be)...

[Bertje]

I checked your pic and to me these lines don't seem original. The curves are not neat enough; especially the way the main line enters from the left and then goes into the pressure valve.

[Popanz]

I thought that the line with the bigger connector that goes into the valve in the middle is a return line for the brake fluid when the pressure is limited. If this would be the case the other line is the pressure line from the master cylinder to the rear brakes. So this line would enter the 2-way splitter, from there to the right rear brake and to the valve where the left rear brake is connected. As the pressure is everywhere the same in this system it doesn't matter where the pressure is regulated. The valve must therefore have two connections just like a splitter and the center connection which is a return when the pressure is droped.

Would this make sence ?

Hjalmar